The present invention relates to methods and system structures for providing public and private telephone service over the Internet and more particularly relates to providing such services through the public telecommunications system including over existing copper telephone lines.
Attention recently has been directed to implementing voice telephone service over the worldwide network now commonly known as the Internet. The Internet had its genesis in U.S. Government (called ARPA) funded research which made possible national internetworked communication systems. This work resulted in the development of network standards as well as a set of conventions for interconnecting networks and routing information. These protocols are commonly referred to as Transmission Control Protocol/Internet Protocol (TCP/IP). The protocols generally referred to as TCP/IP were originally developed for use only through Arpanet and have subsequently become widely used in the industry. TCP/IP is flexible and robust; in effect, TCP takes care of the integrity and IP moves the data. Internet provides two broad types of services: connectionless packet delivery service and reliable stream transport service. The Internet basically comprises several large computer networks joined together over high-speed data links ranging from ISDN to T1, T3, FDDI, SONET, SMDS, OC1, etc. The most prominent of these national nets are MILNET (Military Network), NSFNET (National Science Foundation NETwork), and CREN (Corporation for Research and Educational Networking). In 1995, the Government Accounting Office (GAO) reported that the Internet linked 59,000 networks, 2.2 million computers and 15 million users in 92 countries. It is presently estimated that the growth of the Internet is at a more or less annual doubling rate.
Referring to FIG. 1 there is shown a simplified diagram of the Internet. Generally speaking the Internet consists of Autonomous Systems (AS) which may be owned and operated by Internet Service Providers (ISPs) such as PSI, UUNET, MCI, SPRINT, etc. Three such AS/ISPs are shown in FIG. 1 at 10, 12 and 14. The Autonomous Systems (ASs) are linked by Inter-AS Connections 11, 13 and 15. Information Providers (IPs) 16 and 18, such as America Online (AOL) and Compuserve, are connected to the Internet via high speed lines 20 and 22, such as T1/T3 and the like. Information Providers generally do not have their own Internet based Autonomous Systems but have or use Dial-Up Networks such as SprintNet (X.25), DATAPAC and TYMNET.
By way of current illustration MCI is both an ISP and an IP, Sprint is an ISP, and MicroSoft (MSN) is an IP using UUNET as an ISP. Other information providers, such as universities, are indicated in exemplary fashion at 24 and are connected to the AS/ISPs via the same type connections here illustrated as T1 lines 26. Corporate Local Area Networks (LANs), such as those illustrated in 28 and 30, are connected through routers 32 and 34 and links shown as T1 lines 36 and 38. Laptop computers 40 and 42 are representative of computers connected to the Internet via the public switched telephone network (PSTN) are shown connected to the AS/ISPs via dial up links 44 and 46.
The Information Providers (IPs) constitute the end systems which collect and market the information through their own servers. Access providers are companies such as UUNET, PSI, MCI and SPRINT which transport the information. Such companies market the usage of their networks.
In simplified fashion the Internet may be viewed as a series of routers connected together with computers connected to the routers. In the addressing scheme of the Internet an address comprises four numbers separated by dots. An example would be 164.109.211.237. Each machine on the Internet has a unique address which constitutes one of these four numbers. In the address the leftmost number is the highest number in the Internet hierarchy. By analogy this would correspond to the ZIP code in a mailing address. At times the first two numbers constitute this portion of the address indicating a network or a locale. That network is connected to the last router in the transport path. In differentiating between two computers in the same destination network only the last number field changes. In this example the next number field 211 identifies the destination router. When the packet bearing the destination address leaves the source router the first two numbers are matched in a matrix table to determine how many hops are the minimum to get to the destination. It then sends the packet to the next router as determined from that table and the procedure is repeated. Each router has a database table that finds the information automatically. This continues until the packet arrives at the destination computer. Depending on traffic load, the separate packets that constitute a message may not travel the same path. However they all reach the same destination and are assembled by TCP in their original order. This is in contrast to connection oriented modes such as frame relay and ATM or voice.
One or more companies have recently developed software for use on personal computers to permit two-way transfer of real-time voice information via an Internet data link between two personal computers. In one of the directions, the sending computer converts voice signals from analog to digital format. The software facilitates data compression down to a rate compatible with modem communication via a POTS telephone line. The software also facilitates encapsulation of the digitized and compressed voice data into the TCP/IP protocol, with appropriate addressing to permit communication via the Internet. At the receiving end, the computer and software reverse the process to recover the analog voice information for presentation to the other party. Such programs permit telephone-like communication between Internet users registered with Internet Phone Servers.
The book xe2x80x9cMastering the Internetxe2x80x9d, Glee Cady and Pat McGregor, SYBEX Inc., Alameda, Calif., 1994, ISBN 94-69309, very briefly describes three proprietary programs said to provide real-time video and voice communications via the Internet.
Palmer et al. U.S. Pat. No. 5,375,068, issued Dec. 20, 1994 for Video Teleconferencing for Networked Workstations discloses a video teleconferencing system for networked workstations. A master process executing on a local processor formats and transmits digital packetized voice and video data, over a digital network using TCP/IP protocol, to remote terminals.
Lewen et al. U.S. Pat. No. 5,341,374, issued Aug. 23, 1994 for Communication Network Integrating Voice Data and Video with Distributed Call Processing, discloses a local area network with distributed call processing for voice, data and video. Real-time voice packets are transmitted over the network, for example to and from a PBX or central office.
Hemmady et al. U.S. Pat. No. 4,958,341, issued Sep. 18, 1990 for Integrated Packetized Voice and Data Switching System, discloses an integrated packetized voice and data switching system for a metropolitan area network (MAN). Voice signals are converted into packets and transmitted on the network. Tung et al. U.S. Pat. No. 5,434,913, issued Jul. 18, 1995, and U.S. Pat. No. 5,490,247, issued Feb. 6, 1996, for Video Subsystem for Computer Based Conferencing System, disclose an audio subsystem for computer-based conferencing. The system involves local audio compression and transmission of information over an ISDN network.
Hemmady et al. U.S. Pat. No. 4,872,160, issued Oct. 3, 1989, for Integrated Packetized Voice and Data Switching System, discloses an integrated packetized voice and data switching system for metropolitan area networks.
Sampat et al. U.S. Pat. No. 5,493,568, issued Feb. 20, 1996, for Media Dependent Module Interface for Computer Based Conferencing System, discloses a media dependent module interface for computer based conferencing system. An interface connects the upper-level data link manager with the communications driver.
Koltzbach et al. U.S. Pat. No. 5,410,754, issued Apr. 25, 1995, for Bi-Directional Wire Line to Local Area Network Interface and Method, discloses a bi-directional wire-line to local area network interface. The system incorporates means for packet switching and for using the internet protocol (IP).
Wireless digital communications communications systems such as cellular and PCS telephone networks provide wireless telephone service by providing base stations that communicate over a common air interface with subscribers within a reception range, commonly referred to as cells. As users cross coverage areas of a given base station, a handoff of the telephone call occurs between an active base station and an adjacent base station accepting the call. The base stations are controlled by a base station controller (BSC), that switches the calls between the base stations. The BSC""s are ultimately controlled by a mobile switching center (MSC), which routes calls between the wireless digital communications sytem and the public switched network.
If a call is placed by a wireless telephone user to a destination that is outside the wireless digital communications system, the MSC will route the call to the destination via the public switched network using either a local exchange carrier, an interexchange carrier, or both. Hence, the wireless telephone user may incur landline charges for access of the public switched telephone network.
There is a need to provide a wireless digital communication telephone network that can complete calls initiated by wireless subscribers without requiring access to the public switched telephone network.
There is also a need to provide a wireless digital communication network that can receive telephone calls intended for subscribers and that are received from a source other than the public switched telephone network.
There is a need to provide telephone service via the Internet to users of the public telecommunications network without requiring the use of a computer.
There is also a need to provide an economical and convenient telephone service via the Internet without requiring familiarity with the Internet or its methodology on the part of the user.
There is also a need to provide the public with impulse access to the Internet for voice communications without requiring maintenance of a subscription to an Internet access service.
There is also a need to provide the foregoing types of telephone service over the Internet via the public telephone network without the necessity of reliance on signaling systems of interexchange carriers.
There also exists a need to provide voice service over public telephone systems via the Internet where the use of the Internet is optional to the Telco and transparent to the customer.
These and other needs are attained by the present invention, where encoded digital voice samples received from a digital communications device having a vocoder are decoded in a wireless digital communications system, and the decoded digital voice samples are packetized into data packets for transmission onto a wide area packet switched network. The data packets are received at a destination node on the packet switched network, and the digital voice samples are recovered from the data packets for transmission to a station corresponding to a destination telephone number.
According to one aspect of the present invention, a wireless digital communications system receiving a modulated wireless signal from a digital telephone having a subscriber telephone number includes a system for establishing voice communications between the digital telephone and a destination telephone number using a packet switched network such as the Internet. The modulated wireless signal received by the wireless digital communications system carries encoded, digital voice samples for the destination telephone number. The system of the present invention comprises a wireless transceiver having a demodulator demodulating the received modulated wireless signal and outputting a first data stream carrying the encoded, digital voice samples. A decoder outputs the digital voice samples from the first data stream, and a gateway interface sends and receives packet data from a packet switched network. The gateway interface includes a packet assembler/disassembler that packetizes the digital voice samples into data packets having a destination address corresponding to the destination telephone number, and the gateway interface outputs the data packets onto the packet switched network for reception by a network node corresponding to said destination address.
The present invention enables a wireless digital communications system, for example a digital cellular or PCS system, to bypass local exchange carriers and interexchange carriers by sending and receiving data packets carrying digital voice samples via the packet switched network to a destination network node serving the destination telephone number. If desired, the system of the present invention may also include a transcoder transcoding the encoded digital voice samples for transmission via the public switched telephone network. Hence, the present invention enables a wireless digital communications system to selectively route wireless traffic via the public switched telephone network or the packet switched network.
In another aspect of the present invention, a wireless digital communications system uses a system to send data packets carrying decoded digital voice samples onto a packet switched network. The wireless digital communications system has at least one wireless transceiver that receives a modulated wireless signal from a digital telephone. The modulated wireless signal carries encoded digital voice samples for a destination telephone number. The system of the present invention includes a first interface that receives from the wireless digital communications system a data stream carrying the encoded digital voice samples. The first interface decodes the encoded digital voice samples and packetizes the decoded digital voice samples from the data stream into data packets. The system of the present invention also includes a router assigning a packet address to the data packets in response to the destination telephone number, and a second interface outputting the assigned data packets onto a packet switched network for reception by a network node corresponding to said destination address. Hence, the present invention provides an arrangement enabling a wireless digital communications system outputting encoded digital voice samples from a digital telephone to interface with the packet switched network for two-way voice communications.
Still another aspect of the present invention provides a method for use in a wireless digital communications system. The wireless digital communications system has at least one wireless transceiver receiving a modulated wireless signal from a digital telephone. The received modulated wireless signal carries encoded digital voice samples for a destination telephone number, and the wireless digital communications system in response sends a data stream carrying the encoded digital voice samples. The method of the present invention comprises the steps of decoding the encoded digital voice samples, and packetizing the decoded digital voice samples into data packets. A packet address corresponding to the destination telephone number is assigned to the data packets, and the assigned data packets are sent from a network interface having a network address onto a packet switched network for reception by a network node corresponding to the destination address.
The present invention thus provides an arrangement for providing telephone type services over a packet switched network, such as the Internet, by transporting digital voice samples generated by vocoders in wireless digital communications networks. The present invention also provides an arrangement enabling public switched telephone networks utilizing program controlled switching systems to provide telephone type services over packet switched networks, such as the Internet, for facilitating telephone use of the Internet by digital wireless telephone users on an impromptu basis. A caller is thus able to set-up and carry out a telephone call over the Internet from telephone station to telephone station without access to computer equipment, without the necessity of maintaining a subscription to any Internet service, and without the requiring Internet literacy or knowledge. Calls may be made on an inter or intra LATA, region or state, nationwide or worldwide basis. Billing may be implemented on a per call, timed, time and distance or other basis. Usage may be made of common channel interoffice signaling to set up the call and establish the necessary Internet connections and addressing. Calls may be made from wireless telephone station to wireless telephone station, from wireless telephone station to landline telephone station, or from landline telephone station to wireless station. Calls may also be made from wireless telephone station to computer, or computer to wireless telephone station.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.